Field of the Invention
The invention relates to a communications process for a payment—triggered audiovisual reproduction system.
These audiovisual reproduction systems are generally found in cafes or pubs. This type of system is composed of a sound reproduction machine usually called a jukebox linked to a monitor which displays video images or video clips. To do this the jukebox is equipped with a compact video disk player and a compact video disk library and includes selection buttons which locate the titles of pieces of music which are available. Payment of a proper fee followed by one or more selections authorizes activation of the system with automatic loading in the player of the disk on which the selected piece is found, the desired audiovisual reproduction then being able to start.
These systems, although allowing faithful and good quality reproduction, nevertheless have major defects. Thus, a first defect relates to the space necessary for storing the library; this consequently entails that the system will have large dimensions and will be bulky. Likewise these systems which call on mostly mechanical hardware using sophisticated techniques have high fault rates; this is another defect. Finally, it is very unusual for all the pieces on a disk to be regularly heard; some are almost never played, but still cannot be eliminated. Besides this defect, the additional problems are caused by the companies which manage and distribute these systems. More particularly, placing in the circuit a limited number of identical disks and imposing a certain rotation on their customers sometimes results in an unpleasant wait for the customers when a disk is not available.
In addition, patent application PCT/WO 93 18465 discloses computerized jukeboxes which allow reception via a telecommunications network and a modem connecting the jukeboxes to the network, digital data comprising remotely loaded songs or musical pieces in a mass storage of the jukeboxes. The communications systems is likewise used for remote loading of representative files of digitized graphics information, the songs and graphics files being compressed before they are sent over the network. The jukebox processor then uses these files by decompressing them and sending the graphics data to the video circuit and the song data to the audio circuit.
However, the processor also manages the man/machine interface, and management of these different elements is done by sequentially displaying the graphics images representative of the song, then by responding to the touch action of the user, then checking that the user has paid the prescribed amounts, and finally when the required amount has been accounted, placing the selection in a queue for its subsequent performance. This system can only operate by first displaying the graphics images and then starting performance of the song because the processor cannot, according to the flowcharts, execute two tasks at one time. Finally, the graphics representations are uniquely data digitized by a scanner table of the album cover of the song. In no case does this jukebox allow display of moving images during the broadcast of the song or music. Likewise, since the processor is used for digital data decompression and processing for conversion into audio signals, it cannot consider the new actions of a user making a new selection. This is apparent, notably on page 12 of the PCT application, lines 25 to 27. Selection of new songs can only be done when the jukebox is in the attraction mode, i.e., the mode in which it displays graphics representations of different songs stored in the jukebox in succession.
U.S. Pat. No. 4,956,768 discloses a broadband server for transmitting music or images formed by a main processor communicating by a DMA channel with a hard disk and output cards, each controlled by a supplementary local processor which manages an alternative mode of access to two buffer memories A and B. Memory A is used to deliver, for example, musical data to a user, while the other is filled. Each of the output cards is connected to a consultation station, which can be local and situated in the same vicinity as the server or, alternatively, at a distance and connected by an audio or video communications network. The server receives data block-by-block and ensures that the sample parities are correct and rejects a block including more than two successive wrong samples. Each of these blocks is of course designated by a number. Once a block has been accepted, it can be stored on the local hard disk by recording its ordinal number which has no relation to its physical address on the hard disk. The consultation stations have audio and video outputs such as loudspeakers or headphones and a television monitor which makes it possible to listen to music or display images in response to requests received from terminals included in the consultation stations. In this system, the consultation stations where the first communications processor exists must have specific software for management of selection requests for musical pieces or video. It is only when the request has been made and addressed to the broadband server processor that it can transfer, under the authority of the local processor, the data in the buffer memories, such that this local processor ensures that the data are sent to the consultation stations. Moreover, it is specified that the output cards and buffer memories are filled only after having received the authorization of the local processor of the card.
Consequently, this system can only function within the framework of a multiprocessor device and does not in any way suggest use of this server for a jukebox controlled by a single processor operating in an multitask environment. This system proposed by this U.S. patent thus implements a complex process which allows delivery of a service to several consultation stations; this complex process is thus costly and incompatible with a system of jukeboxes, of which the cost and price should be as low as possible.
Moreover the process of downloading by a central site of digitized audio and video files to the local servers is accomplished via a specialized line communicating unidirectionally with the V35 interfaces of the local server, and allowing passage of 64 kilobit frames. Thus a second parallel communication must be established via the switched telephone network by a serial interface to allow exchange of service data. It is specified that it is preferable to transmit new musical pieces to the broadband server at night to leave the system free for users during the day, and that transmission can be done continuously and simultaneously for all local servers, provided that they can register continuously, i.e., at night.
This device can only work to the extent that the central server is the master and the local servers are slaved. This thus entails availability of local servers at the instant of establishing communications; this is enabled by the local servers having a double processor which relieves the communication processor for a sufficient interval. In a single—processor architecture it is thus difficult to establish communications according to this protocol determined with a variable number of jukebox stations to allow remote operations such as downloading of music or video following a selection by the jukebox manager or sending statistics to the center, or recovering data concerning billing or security management of the units, or recovery for analysis and survey distribution.
The object of the invention is to eliminate the various aforementioned defects of the systems of the prior art, and to provide a system of communications between jukebox units allowing reproduction and display of audiovisual digital information and a central server which supports, among various functions, downloading of data.
This object is achieved by the communications process operating in a conference mode and it includes the following stages:                sending a heading before any transaction which includes the identity of the destination, identity of the sender, and the size of the packets;        sending a server response in the form of a packet of data, each packet sent by the server being encoded using the identification code of the jukebox software;        receiving a data packet by the decoding jukebox, wherein the packet at the same time checks the data received using the CRC method and sending a reception acknowledgment to the server indicating the accuracy of the received data to allow it to prepare and send a new packet to the unit destination.        
According to another operating mode the server can send the data by stream, the stream including several packets, and the receiver unit will then perform decoding and storage, and after receiving the indicator of the last packet, will signal the defective packets received at the server.
According to another feature, each packet contains a first field allowing identification of the seller, a second field allowing indication of the identification of an application, this 32 bit field making it possible to specify whether it is a digital song, digital video, stationary image, software update, statistics, billing, or update of the unit database, a third field indicating the identification of a single type of application such as the identification number of the product, the type of billing, the difference between a midi song and a digital song, last block indication, finally a fourth field indicating the sequence number of the block in the transmission, a fifth block indicating the length of this block in octets, a sixth field composed of variable length data, a seventh field composed of cyclic redundancy verification data.
An object of the invention is to eliminate the various defects of the systems of the prior art by providing an intelligent digital audiovisual reproduction system which is practical to implement, compact, reliable, authorizes storage at the title level as well as easy deletion or insertion of titles not listened to or wanted, all this while maintaining performance and a high level of reproduction quality.
Another object of the invention is to provide a standard protocol which moreover allows the features mentioned above for remote updating of software.
The objects are achieved by the fact that the jukebox units contain software for interpretation of the second field of the communications packets which detect the code corresponding to remote updating of the software and after having verified that the software version number is greater than the version installed on the unit, initiates a system status verification procedure to ensure than there is no activity underway on the jukebox. If yes, the unit displays a wait message, during reception of the new software version on the screen, copies the back—up of the software version installed on the unit, modifies the system startup file for startup with the backup version, then begins execution of the new version of the software, verifies the state of system status after execution of this new version, reinitializes the system startup files for startup with the new version. In the case in which the status is not OK, the software reinitializes the system with the old version and signals a reception error to the central server.
According to another feature, each audiovisual reproduction system contains a multitask operating system which manages, using a primary microprocessor, the video task, the audio task, the telecommunications task, the input task (keyboard, screen, touch) and a status buffer is linked to each of the tasks to represent the activity or inactivity of this task.